Previous research has shown that if two targets are to be identified among
distractors displayed in rapid sequence and each target is masked, correct
identification of the first target hinders identification of the second.
One variable that plays a critical role in this attentional blink (AB),
is visual masking of the second target. Six experiments are presented,
together testing the role of late stage visual processes involved in object
substitution in masking of the second target. Based on the object
substitution hypothesis (Giesbrecht, B. & Di Lollo, V., 1998) the prediction
was that masking the second target by substitution would interact with the
AB, such that stronger masking would produce a more severe deficit.
Although masking by object substitution was observed, it did not interact
with the AB. The results force the rejection of the object substitution
hypothesis and are explained by an alternative hypothesis that the masking
effects that are critical to the AB are mediated by mostly early visual
processes.